1. Technical Field
The present invention relates generally to dragline bucket rigging and more particularly to a pin connector assembly for securing together two components of the rigging.
2. Background Information
Typically, dragline bucket rigging comprises a number of lines in the form of ropes, chains, or cables connected in the form of a series of straight lines and slings and attached between a drag bucket and the main operating cables of a dragline. By variously pulling on selected lines, the bucket may be pulled through the earth collecting material, lifted, maneuvered, and tilted to dump the collected material in a selected location. At the connecting ends of these lines, components of the rigging include various forms of links and yoke shaped members connected together by hard metal connecting pins. For example, draw cables for pulling the bucket to scoop up earthen material may be attached through drag chains secured to opposite sides of the bucket by means of pinned connecting links. Dump cables also connecting to the bucket also connect with the links. Each of the connections to the links includes a yoke-shaped member secured to opposite sides of the link by means of a connecting pin telescoped through the legs of the yoke and the link.
It is important that the pin be securely held within the connection preferably against rotation to avoid premature wearing of the pin and sides of the pin holes and that the mechanism for securing the pin in place be sturdy enough to withstand the harsh environment to which it is exposed. It is also important that it be relatively easy to remove the pin when lines need to be repaired or replaced or when the pin or its retaining mechanism becomes worn excessively.
One prior art form of connection for securing the pin to the yoke member is shown in the accompanying drawing identified as prior art. In this prior art connection, retaining collars are attached to protruding opposite end positions of the pins adjacent the outer sides of the rigging component. With reference specifically to the prior art Fig., each of the collars 10 is assembled from two separate generally U-shaped half pieces 11 and 13. The pieces each include a rigid bridge 14 with inner and outer flat sides 15 and 16 integrally formed with arched legs 17 each of which includes a weld notch 19 at its free end. In assembly with the end of the pin, the inner flat side of the bridge of the upper half piece seats within an upper notch 20 extending in a chordwise direction across an exposed end portion of the pin. The lower half piece of the pin is inserted in a parallel lower notch 21 in the same manner and the two half pieces are welded together at the notches 19. At least one of the collars is welded together after inserting the pin through the two rigging components being connected together. The collars thus act to keep the pin from sliding axially out of the pin holes in the components. To keep the pin from rotating, upper and lower blocks 23 and 24 are welded to the outside of the rigging component adjacent the outer flat sides of the rigid bridge. To remove the pin, at least the notch weld must be cut.